Motorised Pool-Cleaning Device Comprising Freewheel Rotary Movement Means

ABSTRACT

The invention relates to a motorised pool-cleaning device ( 1 ) comprising suction means ( 30 ) and rotary movement means ( 4 ) which define first ( 2 ) and second ( 3 ) bearing axles. Moreover, the rotary movement means, which define at least one ( 2 ) of the first and second bearing axles, comprise first ( 5 ) and second ( 6 ) rotating rollers having respective axes of rotation ( 7, 8 ) which are aligned with said at least one ( 2 ) of the first and second bearing axles. Furthermore, the first ( 5 ) and second ( 6 ) rotating rollers are connected by means of a freewheel connection ( 9 ).

The present invention relates to a motorised pool-cleaning apparatuscomprising suction means and rotary means for displacing the apparatus,which rotary means define first and second bearing axles.

Prior art teaches of such motorised pool-cleaning robots, intended toclean the immersed surfaces of a pool or the like, and the water of saidpool, by moving and rubbing on the surfaces, and by sucking the water ofthe pool into a suction pump, placed in the robot, and expelling itoutwardly therefrom. These robots comprise motorised brush rollers,which are intended to permit the displacement of the robot, on thesurfaces to be cleaned, by adherence and/or sliding, induced by theweight of the robot on the horizontal surfaces, aided by low pressurecaused by the suction of the water, more especially for the verticalsurfaces, and generally by a floating handle, intended substantially topermit the adherence of the robot on the vertical portions. Robots areknown, for example, which comprise four bearing brush rollers, the tworollers of which on one side of the robot are entrained by a firstmotor, and the two other rollers of which, on the other side of therobot, are entrained by a second motor, said first and second motorsbeing controlled by electronics capable of desynchronising the motors,permitting different rotational speeds thereof in order to allowdirectional changes of the robot. Such robots have the disadvantage ofpossessing bulky propulsion means, more especially through the use of aplurality of motors, taking up a lot of space for an apparatus oflimited size, to the detriment of more essential members directlyconnected to the suction functionality of the robot, for example.

In fact, the projected ground area of a pool robot is limited because ofthe loss of low pressure on curved walls which is induced by a distanceto the wall which is all the greater when the robot has an extendedground area and when the curve of the wall of the pool is, of course, ofsmall radius.

In addition, it is noted that the use of a plurality of motors and oftheir associated electronics increases the cost of the robot for nopurpose.

The document GB 2 153 661 is known, which relates to a pool cleanercomprising a body supported by a base carried by driving caterpillars,which are entrained by a mechanism comprising an oscillating plate andentrainment rods, the oscillating plate being set in motion by waterpassing through the casing under the control of the filter pump of thepool which is connected to the cleaner. The cleaner comprises twospindles, situated at the front and at the rear of the cleaner, whichare rotationally entrained by means of entrainment wheels, themselvesrotating as a result of the oscillating plate and a transmission by beltand caterpillars. The two spindles respectively carry, in addition, twoaligned rotating rollers, each formed by flexible vanes, the exteriordiameter of which extends beyond the diameter of the caterpillars,forming sealing means which prevent water from entering beneath thefront and the rear of the cleaner. The wheels of a single spindle arecoupled with an idle motion coupling, which permits, during a fractionof a revolution, only the (caterpillar) wheel connected by drive meansto be entrained during a reversal of the rotary movement, so as to causea rotation of the cleaner on itself through the rotation of only one ofits caterpillars. The vane rollers at the front additionally carry out afunction of wiping the surface to be cleaned, and they send the wastematter wiped off beneath the cleaner. The idle motion couplingnecessarily entrains the robot, during a reverse rotation, in a newdirection, which is predetermined by construction parameters of therobot, such as the diameter of the wheels/rollers and the transmissionparticularly, and the value of the angle of rotation made idle by thecoupling. Such a structure thereby limits the manoeuvring freedom of thecleaner, and its directional possibilities of displacement.

The document US 2002/129839 is also known, which relates to a basin ortank cleaner of the robot type, supported by wheels mounted on fixed ordisplaceable axles which form an acute angle with the longitudinal axisof the body of the cleaner when said cleaner is displaced in one orother of two opposite directions, thereby providing a variabletrajectory while moving forward or backward on the bottom of the basinor tank while cleaning it. This document teaches that the cleanercomprises a single motor, to remove the debris and propel the robot, incombination with directional control means. The control means forchanging the direction of the cleaner are either connected to themobility of the axle or axles carrying the wheels or connected to thechange of direction of a hydraulic propulsion jet. The change ofdirection of the robot according to this document may also be effectedby pressing a displaceable prop on the surface to be cleaned. The meansof changing the direction of such a basin cleaner are all specific,relatively complex and also limiting, relative to the manoeuvringfreedom of the cleaner and to its directional displacementpossibilities.

The present invention permits these disadvantages to be overcome andother advantages to be proposed. More precisely, it consists of amotorised pool-cleaning apparatus comprising:

-   -   suction means,    -   rotary means for displacing said apparatus and defining first        and second bearing axles,        characterised in that:    -   said rotary means, for displacing the apparatus and defining one        bearing axle at least of said first and second bearing axles,        comprise a first and a second rotating roller, the respective        axes of rotation of which are aligned on said one bearing axle        at least of said first and second bearing axles, and in that    -   said first and second rotating rollers are connected by a        freewheel connection.

The freewheel connection between two aligned rollers of one bearing axlepermits the two rotating rollers to be entrained simultaneously in agiven direction of rotation which corresponds to the forward movement ofthe apparatus, which can be called a pool robot when its functioning isautomated, by only motorising one of the rollers. In the reversedirection of rotation of the reduction motor, only the motorised rolleris entrained in reverse rotation, corresponding to the rearward movementof the robot, the other roller no longer being entrained because of thefreewheel. Thus, it is possible to make the robot turn by simplyreversing the direction of rotation of a reduction motor, the robot thenturning substantially about the non-entrained roller and being connectedto the entrained roller by the freewheel connection. Thus, the apparatusaccording to the invention advances in a straight line in the directionof entrainment of the freewheel, and turns on itself when the directionof rotation of the reduction motor is reversed, until the direction ofrotation is reversed again. Appropriate alternative cycles of movingbackward and moving forward may thus permit the apparatus to sweep allof the immersed surfaces of a pool by friction. The freewheel permitsthe apparatus to function by means of a single motor, and allowsinternal space to be freed or the internal members to be arrangeddifferently, for better distribution of the masses and betterdimensions, more especially a reduction in the height of the apparatus.

According to an advantageous feature, the apparatus according to theinvention comprises a single reduction motor, and first means forrotationally entraining one of said first or second rotating rollers bysaid single reduction motor.

The use of a single motor or reduction motor additionally permits acentrifuge suction pump to be housed in the apparatus, for example, moreefficient but more bulky than pumps with traditional vanes, whilekeeping reduced exterior dimensions.

According to another advantageous feature, said rotary means, fordisplacing said apparatus and defining the other bearing axle of saidfirst and second bearing axles, comprise a third and a fourth rotatingroller, the respective axes of rotation of which are aligned on saidother bearing axle of said first and second bearing axles, said thirdand fourth rotating rollers being connected by a freewheel connection.

Thus, two bearing axles, motorised in an identical manner with afreewheel, permit the drive of the apparatus according to the inventionto be improved, while benefiting from the functioning principledescribed above with one motorised bearing axle. The apparatus accordingto the invention, provided with four brush rollers, advances in astraight line in the direction of entrainment of the freewheels, andturns on itself when the direction of rotation of the reduction motor isreversed.

According to another advantageous feature, the apparatus according tothe invention comprises in addition second means for rotationallyentraining one of said third or fourth rotating roller by said singlereduction motor.

According to another advantageous feature, the apparatus according tothe invention comprises a support on which is secured said singlereduction motor, first and second lateral caterpillar means on saidsupport on both sides thereof, first and second means for entrainingsaid first and second caterpillar means respectively, associated withone at least of said first or second bearing axles, said first andsecond entrainment means being connected to said support by means of aconnection with a degree of rotational freedom.

The caterpillar means permit the apparatus according to the invention tocross obstacles which cannot be crossed with the single rotatingrollers, for example steps.

According to another advantageous feature, said support comprises afirst portion in the form of a U, on which is secured said singlereduction motor, a first and a second lateral casing closing the openlateral ends of the U, secured respectively in a releasable manner onsaid first portion of the support and carrying said rotary means fordisplacing the apparatus.

According to another advantageous feature, said first and second lateralcasings respectively carry, in addition, the first and second means forentraining said first and second caterpillar means, and said first andsecond rotating rollers and said third and fourth rotating rollers areplaced in an overhanging manner on the side of said first and secondlateral casings respectively turned towards the first U-shaped portionof the support, said first and second means for entraining said firstand second caterpillar means being respectively placed in an overhangingmanner on the opposite side of said lateral casings.

The overhanging mounting of the rotating rollers and of the caterpillarentrainment means permits easy access to these means by an operator, asthey are all advantageously visible without any dismantling.

According to another advantageous feature, said freewheel connection orconnections comprises or comprise, respectively, a helical resilientwasher and at least one lug capable of abutting against one end of saidhelical washer in a first direction of rotation, and of sliding on saidhelical washer in the second opposite direction of rotation.

According to another advantageous feature, said suction means comprise apump of the centrifuge type.

According to another advantageous feature, said first and second meansfor entraining said first and second caterpillar means compriserespectively four driving wheels, connected in groups of two by means ofa first and a second transmission belt.

According to another advantageous feature, the apparatus according toinvention comprises two fixed gripping handles, disposed below an upperlevel which is defined by the highest surface of said apparatus.

According to another advantageous feature, said two fixed grippinghandles are parallel to said first and second bearing axles and disposedabove these bearing axles.

According to another advantageous feature, said first and second means,for rotationally entraining one of said first or second rotating rollersand one of said third or fourth rotating rollers, comprise said firstand second transmission belts.

Other features and advantages will appear on reading the followingdescription of one embodiment of a motorised pool-cleaning apparatusaccording to the invention, together with the accompanying drawings, anembodiment given by way of non-limiting illustration.

FIG. 1 is a perspective fragmentary partial plan view of one embodimentof a motorised pool-cleaning apparatus according to the invention;

FIG. 2 is a perspective fragmentary plan view of one detail in FIG. 1;

FIG. 3 is a perspective underneath view of an enlarged detail of FIG. 1;

FIG. 4 is a perspective plan view of the example in FIG. 1, partiallyassembled;

FIG. 5 shows an enlarged assembly detail of the apparatus in FIG. 1;

FIG. 6 is a perspective plan view of the embodiment in FIG. 1, with asupplementary member in partially fragmentary view;

FIG. 7 is a perspective plan view of the complete embodiment in FIG. 1;

FIG. 8 shows an enlarged assembly detail of the apparatus in FIG. 5; and

FIGS. 9 and 10 are perspective and cross-sectional (FIG. 9) views of anenlarged detail of FIG. 7.

The motorised pool-cleaning apparatus 1 illustrated in FIG. 1 comprises:

-   -   suction means 30,    -   rotary means 4 for displacing the apparatus and defining the        first 2 and second 3 bearing axles, comprising respectively a        first 5 and a second 6 rotating roller, the respective axes of        rotation 7,8 of which are aligned on the first bearing axle 2,        and advantageously a third 10 and a fourth 11 rotating roller,        the respective axes of rotation 12, 13 of which are aligned on        the second bearing axle 3,    -   the first 5 and second 6 rotating rollers being connected by a        freewheel connection 9, and    -   the third 10 and fourth 11 rotating rollers being connected by a        freewheel connection 14,    -   preferably a single reduction motor 15, first means 16 for        rotationally entraining one of the first 5 or second 6 rotating        rollers by the single reduction motor, in this case the first        rotating roller 5 in the example illustrated, and second means        17 for rotationally entraining one of the third 10 or fourth 11        rotating rollers by the single reduction motor 15, in this case        the third rotating roller 10 in the example illustrated in FIG.        1,    -   advantageously a support 18 on which is secured the single        reduction motor 15, first 19 and second 20 lateral caterpillar        means on the support 18 on both sides of said support, first 22        and second 23 means for entraining the first 19 and second 20        caterpillar means associated with the first 2 and second 3        bearing axles respectively, the first 22 and second 23        entrainment means being connected to the support 18 by means of        a connection with a degree of rotational freedom.

The suction means 30 advantageously comprise a pump of the centrifugetype 31, more efficient than a vane pump and also more bulky, buthousable in the support 18, which is advantageously in the form of a Uas illustrated in FIG. 1, thanks to the use of a single reduction motor.The reduction motor 15 and the centrifuge pump 31 are positionedcentrally in the axis of the U, and preferably aligned along thelongitudinal axis of the U, in order to free a space for the filters(not illustrated for reasons of clarity in the Figure) on both sides ofthe reduction motor 15 and pump 31 assembly, in front of and behindthese members. The water is sucked into the apparatus 1 through orifices32 provided in the lower portion of the U which forms the support 18, asillustrated in FIG. 1 or 4, then passes through the filters placedabove, then enters the inlet opening 33 of the centrifuge suction pump31, in order to be forced-back through the outlet opening 34 of thispump, which outlet terminates on the upper surface of the apparatus, asillustrated in FIG. 7.

The rotating rollers 5, 6, 10 and 11 are advantageously identical andeach formed by two half-shells 35 and 36, screwed one onto the other inorder to form a cylinder of circular cross-section as illustrated inFIG. 5, which shows, in a fragmentary view, two rotating rollers formingone of the two bearing axles 2, 3. One end of the half-shells includesat least one lug, which has the function of entraining the freewheel 9placed between two rollers and connecting these rollers by a connectionwhich rotates in only one direction. In addition, said end of thehalf-shells includes a supplementary lug 37 for the rotationalimmobilisation of the freewheel on one of the two aligned rollers, sothat the driven roller entrains the other aligned roller in onedirection of rotation and no longer entrains it in the oppositedirection of rotation. It is to be noted that, in FIG. 5, one half-shellof a roller has not been illustrated, in order to permit the freewheelto be seen. Each-half shell advantageously includes, at each end, ahalf-bore, the appropriate shape of which permits a connection of therollers to the apparatus, more particularly to the support, according toa connection with a degree of rotational freedom. The cylindricalsurface of each rotating roller is covered with a flexible brush of anyknown kind, for example formed from elastomer, secured on the roller,capable of transmitting the drive couple and of ensuring the adherenceof the apparatus on the walls of a pool.

The freewheel connections 9, 14 include a helical resilient washer 38,rotationally connected to one of the rollers of the bearing axle 2, 3respectively, and at least one lug 37, which is integral with the otherroller of the bearing axle in question, capable of abutting against thewasher 38 in a first direction of rotation, more particularly ofabutting against the radial portion 39 projecting axially from thehelical washer, as illustrated in FIG. 8, and of sliding on said portionin the second opposite direction of rotation, as a result of itselasticity. The resilient washer 38 is rotationally connected to one ofthe rollers of the bearing axle, for example by means of a lug 37 whichpenetrates into a housing 60 of the helical washer 38. In a preferentialmanner, each rotating roller 5, 6, 10 and 11 includes two diametricallyopposed lugs, and each washer includes two corresponding, diametricallyopposed housings 60, in which are respectively accommodated the two lugs37 of a roller. One of the housings 60, provided on the resilient washer38, preferably intercepts the radial stop member 39, as illustrated inFIG. 8, so that the lug 37 of the roller which is not rotationallyconnected to the washer 38 can press against a stop member 39, profiledin a cylindrical form complementary to that of the lug in order toensure a better distribution of the forces. It is to be noted that FIG.5 illustrates, differently from FIG. 8, another embodiment of theresilient washer 38, in which the housing 60 provided on this washerdoes not intercept the radial stop member 39. As illustrated in FIG. 1,the helical resilient washer 38 may include an axle 40, which projectsaxially on both sides of the washer and permits rotational guidance inthe ends of the aligned rollers between which it is disposed.

The support 18 advantageously comprises a first portion 24 in the shapeof a U, on which is secured the single reduction motor 15, a first 25and a second 26 lateral casing which close the open lateral ends of theU, secured respectively in a releasable manner, for example by a screw,on the first portion 24 of the support 18, and carrying respectively therotating rollers 5, 6 and 10, 11.

The transmission of the driving movement of the reduction motor 15 tothe rotating rollers 5 and 10, which are integral with the first lateralcasing 25, is advantageously effected in the following manner via thefirst 16 and second 17 rotational entrainment means: the driving spindleof the reduction motor is provided with an entrainment pinion 41, inengagement with two transmission pinions 42, 43, which are integral withthe lateral casing 25 by a connection with a degree of rotationalfreedom. The rotational movement of the transmission pinions is thentransmitted to the rollers 5 and 10 via a first 27 and a second 28synchronous transmission belt, respectively, in contact with two pulleys44, 45 which are rigidly connected to the two transmission pinions 42,43, and with two pulleys 46, 47 which are rigidly connected to the tworotating rollers 5, 10 respectively, as illustrated in FIG. 2 or 3. Thebearing axles 2 and 3, the rotational axes of the transmission pinions42, 43 and of the driving pinion 41, as well as the axes of rotation ofthe pulleys 44, 45, 46, 47 are advantageously horizontal and parallel.

As illustrated in FIG. 1, 2 or 3, the first 25 and second 26 lateralcasings respectively carry, in addition, the first 22 and second 23entrainment means of the first 19 and second 20 caterpillar means, andthe first 5, second 6, third 10 and fourth 11 rotating rollers areplaced in an overhanging manner on the side of the first 25 and second26 lateral casings respectively turned towards the first U-shapedportion 24 of the support 18, the first 22 and second 23 entrainmentmeans of the first 19 and second 20 caterpillar means being respectivelyplaced in an overhanging manner on the opposite side of the lateralcasings 25, 26.

The first 22 and second 23 entrainment means of the first 19 and second20 caterpillar means comprise respectively four driving wheels 48, 49,50, 51, connected in groups of two advantageously by means of the first27 and second 28 transmission belts.

The four driving wheels 48, 49, 50, 51 each advantageously assume theform of a rim with lateral edges, as shown in FIG. 1, 2 or 3, on whichrim the caterpillar means is placed and adheres by friction. These rims48, 49, 50, 51 each include a central groove capable of housing thecorresponding belt 27, 28, so that the exterior diameter of the belt isless than the diameter of the rim on which the caterpillar rests. Thecaterpillars can extend beyond the edge of the wheels, for example withcaterpillar clamps covering the edge of the wheels, and thereby preventa hard portion of the apparatus, in this case the edge of the wheels,being able to come into contact with the coating of the pool, thecaterpillars advantageously being made from flexible material of theelastomeric type or similar, while the wheels will preferably be madefrom a hard material of the rigid plastics material type.

FIG. 3 shows a lateral transmission assembly made up of two rotatingwheels 5 and 10, the four driving wheels 48, 49, 50 and 51 forentraining the caterpillar, connected two by two by a belt 27, 28, andthe lateral casing 25 connecting these members, and FIG. 2 shows the twolateral transmission assemblies, which are advantageously identical, therotating wheels 5, 6 and 10, 11 of which are respectively connected bythe freewheel connections 9 and 14. It is evident that, for reasons ofsimplifying the production of the apparatus described, the two lateraltransmission assemblies include transmission pinions 42 and 43, makingthese assemblies perfectly identical, while only one of these assemblieswould necessitate the presence of such pinions, namely the assembly ofwhich the transmission pinions are in contact with the pinion of thereduction motor 15. The purpose of having two identical transmissionassemblies is of course obvious, from the point of view of reducing themanufacturing costs.

The end wheels 48, 51 of the caterpillars 19, 20 are advantageouslyaligned on the bearing axles 2 and 3 defined respectively by the axes ofrotation of the rotating rollers 5, 6, 10 and 11, more especially inorder to improve the guidance of the caterpillars. The end wheels 48 and51 are associated, in a rigid and dismantlable manner, with thecorresponding rotating roller through the intermediary of a spindletraversing the lateral casing in a bearing provided for this purpose,and penetrating into an appropriate bore of the roller. In addition, thefour driving wheels 48, 49, 50 and 51 for entraining the caterpillarpossess axes of rotation situated in the same horizontal plane, and thispermits a very flat apparatus to be proposed.

It is to be noted that a caterpillar has not been illustrated in FIGS.2, 3 and 4 in order to show the driving wheels for entraining saidcaterpillar, as well as the transmission belts. The exterior diameter ofthe driving wheels 48, 49, 50, 51 is designed so that the caterpillardoes not hinder the motorisation of the apparatus by the rotating wheels5, 6, 10 and 11, which must have, with their brush, a diameter greaterthan that of the caterpillars. In fact, it needs to be remembered thatthe caterpillars are only used when an obstacle is present during thedisplacement of the apparatus, so that the drive of the bearing axles 2or 3 is insufficient to ensure its movement.

FIG. 6 repeats the illustration of FIG. 1 while adding an upper hood 52,which closes the upper portion of the apparatus and, more particularly,the motor compartment comprising the reduction motor, the centrifugepump and the filters (not illustrated). The hood, advantageously screwedonto the support 18, includes an opening intended to permit the water tobe forced-back by the pump, and also advantageously includes accessflaps 53 and 54 to these filters for their maintenance. The access flaps53 and 54 are advantageously deprived of locking, in order to simplifymanipulation, and make access to the filters very easy. During thefunctioning of the apparatus, the access flaps are kept flattened by thesuction low pressure. When the pump is stopped, the access flaps, whichare advantageously hinged on one of their sides and on the upper hood,serve as emptying valves by opening freely during the removal of therobot from the pool. This configuration offers an advantageous throughcross-section for the water, and limits the number of discharge orificesin the robot. The filters will preferably be formed by a rigid cassettewhich contains the filtration material.

The extreme simplicity of the structure of the apparatus according tothe invention will be noted, said structure being reduced to:

-   -   a U-shaped support on which are secured the reduction motor and        pump members,    -   two lateral casings secured to the U-shaped support, which can        be rapidly dismantled and include all of the transmission and        the members connected with the drive of the apparatus,    -   freewheels inserted between the two lateral groups, and    -   an upper hood for closing the motor compartment.

The caterpillars with their driving wheels are advantageously placed inan overhanging manner on the lateral casings, so that they are entirelyvisible and access for maintenance is achieved without having todismantle any structural member.

Two fixed handles 57 will advantageously be added to permit theapparatus to be gripped by the user in order to transport it to theplace of use. Such fixed handles 57 may, for example, assume the form oftwo bars 58, advantageously parallel respectively to the bearing axles 2and 3 and placed substantially above these bearing axles, as illustratedin FIG. 7. These handles 57 may be made integral with the upper hood 52or with any other structural member of the apparatus, and participate inthe resistant structure thereof, but should preferably not extend abovethe highest upper surface of the apparatus, namely, in the exampleillustrated, not extend above the upper hood 52, in order not toincrease the height of the apparatus and not to hinder the displacementof the electric cable 61, as will be explained in more detail below.

The centrifuge pump is advantageously made up of two distinct parts, themotor with its turbine on the one hand and the guide 55 for the fluidflow on the other hand, individually screwed to the base of the support18, the flow guide having its outlet in the upper portion of theapparatus at the opening 34 illustrated in FIG. 1. The flow guideadvantageously serves as an attachment, for example at a point 56 in thevicinity of the outlet 34, for an electric connector 62, preferablyrotary, of the electric supply cable 61 of the reduction motor 15 and ofthe suction pump 31. In the event of abnormal tension on the electriccable, the flow guide is capable of resisting this force withouttransmitting it either to the sealing casing of the pump motor or to theupper hood 52 of the apparatus.

It is to be noted that fluid penetrates into the apparatus, with theexception of the electric motors which must be placed in sealedprotective casings according to any known method, the electric connector62 which must be sealed as explained hereinafter by means of FIGS. 9 and10, and more generally with the exception of all of the electricmembers.

The electric supply cable 61 of the apparatus is fitted, at one end,with the preferably rotary electric connector 62 and, at the other end,with a standard connector (not illustrated) for an electric connectionto an electric supply box. The electric cable 61 is made up, forexample, of a sheath 63 formed from flexible PVC, normally fitted withfive electric wires 64 in the interior thereof, the immersed end 65 ofthe cable preferably being sealed to ensure a presence of air in theinterior of the sheath 63, so necessary for the flotation of the cable.The rotary connector 62 advantageously serves as an attachment strap forthe cable, directly or indirectly, and prevents it from kinking.

As illustrated in FIGS. 7, 9 and 10, the electric connector 62 ispreferably rotational along a vertical axis 66, with a radial horizontalinlet for the supply cable 61 on a turning portion 67 of the connector62. Thus, the rotation of the turning portion 67 of the connector 62 isinduced by the displacement inertia of the cable 61 and not by itstorsional resistance, and this prevents the electric cable from beingsubjected to excessive fatigue forces, extending its service life andfacilitating its manipulation. Thus, the supply cable 61 does notrequire any specific torsional performance in order to make the turningportion 67 of the connector 62 turn.

The electric connector 62 is now going to be described in more detailwith one embodiment according to FIGS. 9 and 10.

The turning portion 67 of the connector comprises a turret 80, whichadvantageously assumes a substantially cylindrical general shape, with acircular cross-section, the axis of symmetry of which is intended to bevertical, and includes a sealed radial inlet 69 for the electric cable61. In the axis of the turret 80 is disposed a connection tube 70, whichis secured to said turret by means of one rotating connection 79 atleast and in the interior of which connection tube are disposed theelectric wires 64 of said electric cable 61, respectively connected toconductor paths 71, arranged vertically and respectively formingcylindrical conductor rings with a circular cross-section on theexterior surface of the connection tube, in order that each electricalwire is capable of ensuring an electric connection via its circularpath.

The fixed portion 68 of the connector 62 includes a guide tube 72 with acircular cross-section, enclosing the connection tube 70 and connectedto the turning portion 67 by a connection with a degree of rotationalfreedom. The tube 72 is preferably intended to be secured in a connectorstrap 73, as shown in FIG. 9, which strap is itself secured to theapparatus via the guide 55 for the flow, for example. The turningportion 67 of the connector 62 is advantageously connected to theconnector strap 73 through the intermediary of the turret 80 by aconnection 74, which has a degree of rotational freedom and is intendedto transmit the mechanical forces between the electric cable 61 and theapparatus in order to avoid pulling on the electric connection. As shownin FIG. 9, the guide tube 72 includes an interior surface provided witha number of transverse conductor strips 75, arranged to correspond withthe number of circular paths 71 of the connection tube 70, each strip 75being capable of coming into contact by friction with the correspondingconductor path 71, so as to ensure an electric connection over 360° whenthe electric cable 61 effects a complete revolution, that is to say whenthe turning portion 67, and more specifically the connection tube 70,effects a complete rotation in the guide tube 72. The electric wires 76,which are intended to supply the appropriate electric members in theapparatus and are respectively connected to the strips 75, emerge fromthe guide tube 72 through the lower portion thereof.

FIG. 10 illustrates the turning portion 67, which is provided with theguide tube 72 and with the electric cable 61, insulated from theconnector strap 73.

The connection tube 70 advantageously includes insulating collars 77,each assuming a circular washer shape, separating the circular conductorpaths 71 from one another, and the exterior cylindrical surface of whichserves advantageously as a guide surface for the tube 70 in the tube 72,as illustrated in FIG. 9. The assembly of the tubes 70 and 72 mayadditionally include a rotating guide block 78. The connection 79between the connection tube 70 and the turret 80 will at least be arotating connection but, in a preferred manner, a clearance will be leftbetween the two portions of the connection in order that the forcestransmitted to the turret 80 by the electric cable 61 are nottransmitted to the connection tube 70, thereby avoiding pulling on theassembly of rotating connections between the connection tube 70 and theguide tube 72.

The sealing of the electric connector 62 will advantageously be ensuredon the one hand by a lip joint 81 placed between the connection tube 70and the guide tube 72, in the upper portion of these elements at thelevel of the connection 74 between the turret 80 and the strap 73, andon the other hand in the base of these two tubes by a sealed resinstopper, for example blocking the base of the guide tube 72, therebyprotecting all of the rotating connections between these two sealingpoints. The inlet of the connection tube 70 will be able to be providedwith a sealed resin stopper in order to prevent liquid, which is beingintroduced into the turret 80, from penetrating the interior of the tube70, where the connections of the supply wires to the circular conductorpaths is effected. The turret 80, as well as the strap 73, willadvantageously be provided in the form of two half shells, screwed oneonto the other, thereby proposing a simple means to achieve theconnection 74 with a degree of rotational freedom, and the rotatingconnection 79, for example of the one-piece cotter-pin, lug or groovestype, and an efficient means to achieve the sealed connection of theelectric cable 61 with the turret 80 by pressure of the two half-shellson the exterior sheath 63 of the cable 61.

The apparatus according to the invention may be provided with any knownmeans which permits its functioning to be automated, for example of thedelay and reverse reduction motor drive type.

It is to be noted that the apparatus according to the invention permitsthe use of a conventional floating handle to be avoided, because of alow centre of gravity which permits the adherence of the robot onvertical parts to be optimised. The absence of the second reductionmotor additionally permits space to be freed to position an internalfloat (not illustrated), which advantageously replaces the floatinghandle, this internal float, produced for example from polystyrene,having a more reduced volume the lighter the robot is. The internalfloat will preferably be housed beneath and above the reduction motor,assuming the form of a plate for example. The internal float willadvantageously be able to assume any appropriate shape, moulding itselfinto the free spaces in the interior of the U-shaped support.

The absence of a floating handle permits the upper portion of theapparatus to be freed of any displaceable member, more precisely to freethe portion of the apparatus situated above the upper hood 52, and toadopt a rotary connector 62 with a radial inlet which extends, for itspart, at least to the level of its radial inlet, above the highest levelof the upper hood. One advantage provided by the reduced height of theapparatus according to the invention is to be able to use it on bathingareas which are not very deep.

1. Motorised pool-cleaning apparatus (1) comprising: suction means (30),rotary means (4) for displacing said apparatus and defining first (2)and second (3) bearing axles, characterised in that: said rotary means,for displacing the apparatus and defining one bearing axle (2) at leastof said first and second bearing axles, comprise a first (5) and asecond (6) rotating roller, the respective axes of rotation (7, 8) ofwhich are aligned on said one bearing axle (2) at least of said firstand second bearing axles, and in that said first (5) and second (6)rotating rollers are connected by a freewheel connection (9). 2.Apparatus according to claim 1, characterised in that it comprises asingle reduction motor (15), and first means (16) for rotationallyentraining one of said first (5) or second (6) rotating rollers by saidsingle reduction motor.
 3. Apparatus according to claim 2, characterisedin that said rotary means (4), for displacing said apparatus anddefining the other bearing axle (3) of said first (2) and second (3)bearing axles, comprise a third (10) and a fourth (11) rotating roller,the respective axes of rotation (12, 13) of which are aligned on saidother bearing axle (3) of said first (2) and second (3) bearing axles,and in that said third (10) and fourth (11) rotating rollers areconnected by a freewheel connection (14).
 4. Apparatus according toclaim 3, characterised in that it comprises in addition second means(17) for rotationally entraining one of said third (10) or fourth (11)rotating roller by said single reduction motor (15).
 5. Apparatusaccording to claim 2, characterised in that it comprises a support (18)on which is secured said single reduction motor (15), first (19) andsecond (20) caterpillar means lateral to said support on both sidesthereof, first (22) and second (23) means for entraining said first andsecond caterpillar means respectively, associated with one at least ofsaid first (2) or second (3) bearing axles, said first and secondentrainment means being connected to said support by means of aconnection with a degree of rotational freedom.
 6. Apparatus accordingto claim 5, characterised in that said support (18) comprises a firstportion (24) in the form of a U, on which is secured said singlereduction motor (15), a first (25) and a second (26) lateral casingclosing the open lateral ends of the U, secured respectively in areleasable manner on said first portion of the support and carrying saidrotary means (4) for displacing the apparatus.
 7. Apparatus according toclaim 6, characterised in that said first (25) and second (26) lateralcasings respectively carry, in addition, the first (22) and second (23)means for entraining said first (19) and second (20) caterpillar means,in that said first (5) and second (6) rotating rollers and said third(10) and fourth (11) rotating rollers are placed in an overhangingmanner on the side of said first (25) and second (26) lateral casingsrespectively turned towards the first U-shaped portion (24) of thesupport (18), said first (22) and second (23) entrainment means of saidfirst (19) and second (20) caterpillar means being respectively placedin an overhanging manner on the opposite side of said lateral casings.8. Apparatus according to claim 1, characterised in that said freewheelconnection or connections (9, 14) comprises or comprise, respectively, ahelical resilient washer and at least one lug capable of abuttingagainst one end (39) of said helical washer in a first direction ofrotation, and of sliding on said helical washer in the second oppositedirection of rotation.
 9. Apparatus according to claim 1, characterisedin that said suction means (30) comprise a pump (31) of the centrifugetype.
 10. Apparatus according to claim 5, characterised in that saidfirst (22) and second (23) means for entraining said first (19) andsecond (20) caterpillar means comprise respectively four driving wheelsconnected in groups of two by means of a first (27) and a second (28)transmission belt.
 11. Apparatus according to claim 4, characterised inthat said first (16) and second (17) means for rotationally entrainingone of said first (5) or second (6) rotating roller, and of one of saidthird (10) or fourth (11) rotating roller, comprise a first (27) and asecond (28) transmission belt.
 12. Apparatus according to claim 1,characterised in that it comprises two fixed gripping handles (57),disposed below an upper level which is defined by the highest surface ofsaid apparatus.
 13. Apparatus according to claim 12, characterised inthat said two fixed gripping handles (57) are parallel to said first (2)and second (3) bearing axles and disposed above these bearing axles. 14.Apparatus according to claim 1, characterised in that it comprises arotary electric connector (62) for a connection to an electric supplycable (61), which connector permits this supply cable to be connected tosaid apparatus according to a connection which has a degree ofrotational freedom.
 15. Apparatus according to claim 1, characterised inthat said rotary means (4), for displacing said apparatus and definingthe other bearing axle (3) of said first (2) and second (3) bearingaxles, comprise a third (10) and a fourth (11) rotating roller, therespective axes of rotation (12, 13) of which are aligned on said otherbearing axle (3) of said first (2) and second (3) bearing axles, and inthat said third (10) and fourth (11) rotating rollers are connected by afreewheel connection (14).
 16. Apparatus according to claim 3,characterised in that it comprises a support (18) on which is securedsaid single reduction motor (15), first (19) and second (20) caterpillarmeans lateral to said support on both sides thereof, first (22) andsecond (23) means for entraining said first and second caterpillar meansrespectively, associated with one at least of said first (2) or second(3) bearing axles, said first and second entrainment means beingconnected to said support by means of a connection with a degree ofrotational freedom.
 17. Apparatus according to claim 4, characterised inthat it comprises a support (18) on which is secured said singlereduction motor (15), first (19) and second (20) caterpillar meanslateral to said support on both sides thereof, first (22) and second(23) means for entraining said first and second caterpillar meansrespectively, associated with one at least of said first (2) or second(3) bearing axles, said first and second entrainment means beingconnected to said support by means of a connection with a degree ofrotational freedom.